03 Mountainer 4.6 motor

squeak93

15 Year Member
Jun 2, 2005
2,141
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Joplin, Missouri
Ok, I just bought this 22k mile gem for 1k.(aluminum block ftw) Full motor, lower intake to pan obviously. My npi motor is stock and blown up so I figured this is my cheapest and best bet to get a pi swap and a good motor w/o having to jack with rebuilding and finding all the swap parts.

So my question is, Other than the front timing cover and a few sensors.... Should I expect any issues or just enjoy a nice easy motor swap? (I built 100% of my last pushrod motor, so not a newb here). Just trying to make sure I don't have any real suprises like valve covers not clearing or something stupid like that. Not done to much work to mod cars, always been foxes.
 
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Not sure if you will have any suprises, I'm answering because I just recently purchased a 2004 Mountaineer with 35K miles. I do know the motor only has 239hp which is less than a PI Mustang's 260. I haven't really looked into the differences between the 2 engines yet so can't offer any advice yet. I'm still trying to get used to the vehicle and haven't ventured much into the engine compartment yet.
 
As far as I understand it, the difference is in the Tune and set up. The exhaust and trans/rear combo rob more from the exploders and mountainiers.

They way I understand it, beside from the Aluminum block, the motors are identical.

Anyone want to chime in there?
 
Looked mine over a bit, they are virtually identical. One minor difference is the alternators are different, at least the mounting is different so definetly a different alternator. Could have the same amperage, but I have no info available on that.

I'd say the major difference is in the tune and exhaust, since it goes to a single muffler. The hp difference is at the crank so no tranny or rear end to make a difference there (AWD is awesome though!). I hadn't noticed it was an aluminum block, thanks for pointing it out. :nice:

No matter what its got to be an upgrade over your NPI motor.
 
May look visually the same but my guess is that the cams and/or heads have some differances in them and that is where the additional HP from the Mustang comes. Again, I am not a 4.6 expert (5.0L only) but it makes sense.